^Dowsett, Peter (2015). Audio Production Tips: Getting the Sound Right at the Source, p.3.6.3. CRC. ISBN9781317614203. "The minor third, however, does not appear in the harmonic series until the nineteenth harmmonic. Your ear almost expects to hear the major third ([on A:] C♯), and when that is replaced with a more distantly related note, this makes the listener feel more 'unpleasant', 'tense', or 'sad'."